Originally Posted by |M|B.M.F.
Hey bob, I just ordered in the AIX blu Ray Audio Calibration Disc HD Music Sampler specifically to help check the phase of the sub with my main speakers. I do not see a test chapter for this. They have a phase chapter but it does not inlcude a comparison with the sub. What are you using?
Use System Calibration > Subwoofer Crossover Test
This will sweep a test tone back and forth across the crossover frequencies.
Use it like this:
IMPORTANT NOTE: Be sure your speaker distance settings are correct before you adjust Phase for the sub, as phase is also a function of relative distance.
1) Do an ARC setup. This will establish the crossover frequencies, volume balance the speakers, and eliminate any response defects from the speakers that will interfere with your ability to hear phase related changes.
2) Run the Subwoofer Crossover Test and listen to see if you have uniform volume all across the range. Since ARC has already balanced things and removed defects, any dip you hear will be due to phase cancellation between the Sub and LF. Since different setups will have different crossover frequencies, that dip may occur higher or lower in the sweep range in your setup.
3) Adjust sub phase to eliminate any such dip and get as close as you can get to uniform volume across the frequency range of this test.
Note that phase settings near the correct setting will sound very similar. Add to that some typical listener bias and you'll see that you may undershoot or overshoot the correct phase setting. To counter that, find phase two ways: First sneaking up from below and second dropping down from above. If you come up with two different answers then split the difference between them and that will be your correct phase setting.
4) If you have only one sub, you are now done. Your prior ARC solution still applies and will now just work better. If you have more than one sub then you must re-Measure for ARC after changing phase for any sub as phase setting changes will change what ARC hears from the combo of subs playing together.